<template>
  <div id="home">
    <!-- 导航 -->
    <nav-bar class="home-nav">
      <template #center>
        <div>购物街</div>
      </template>
    </nav-bar>
     <tab-control
        :titles="['流行','新款','精选']"
        @tabClick="tabClick"
        ref="tabControl1"
        class="tab-control"
        v-show="isTabFixed"
        ></tab-control>
    <scroll class="wrapper" ref="scroll"
            :probe-type="3"
            @scroll="contentScroll"
            :pull-up-load="true"
            @pullingUp="loadMore"
            >
        <!-- 轮播图 -->
        <home-swiper :banners="banners" @swiperImageLoad="swiperImageLoad"/>
        <!-- 推荐 -->
        <recommend-view :recommends="recommends"></recommend-view>
        <feature-view></feature-view>
        <tab-control
        :titles="['流行','新款','精选']"
        @tabClick="tabClick"
        ref="tabControl2"></tab-control>
        <goods-list :goods="showGoods"></goods-list>
    </scroll>
    <back-top @click.native="backClick" v-show="IsBackTop"/>
  </div>
</template>

<script>
import {getHomeMultidata,getHomeGoods} from 'api/home'
import {debounce} from 'common/utils'

import NavBar from 'components/common/navbar/NavBar';
import TabControl from 'components/content/tabControl/TabControl';
import GoodsList from 'components/content/goods/GoodsList';
import Scroll from 'components/common/scroll/Scroll';
import BackTop from 'components/content/backTop/BackTop';

import HomeSwiper from './childComps/HomeSwiper';
import RecommendView from './childComps/RecommendView';
import FeatureView from './childComps/FeatureView';
import {itemListenerMixin} from 'common/mixin'

export default {
  name: 'Home',
  components: {
    NavBar,
    TabControl,
    HomeSwiper,
    RecommendView,
    FeatureView,
    GoodsList,
    Scroll,
    BackTop,
  },
  data(){
    return {
      banners: [],
      recommends: [],
      goods: {
        'pop': {page: 0, list: []},
        'new': {page: 0, list: []},
        'sell': {page: 0, list: []},
      },
      currentType: 'pop',
      IsBackTop: false,
      tabOffsetTop: 0,
      isTabFixed: false,
      saveY: 0,
      ItemImgListener: null
    }
  },
  computed:{
    showGoods(){
      return this.goods[this.currentType].list;
    }
  },
  activated(){
    this.$refs.scroll.refresh()
    this.$refs.scroll.scrollTo(0,this.saveY,0)
  },
  deactivated(){
    this.saveY = this.$refs.scroll.getScrollY()
    this.$bus.$off('imageLoad', this.ItemImgListener)
  },
  created(){
    // 1.请求多个数据
    this.getHomeMultidata()

    // 2.请求商品数据
    this.getHomeGoods('pop')
    this.getHomeGoods('new')
    this.getHomeGoods('sell')

  },
  mounted(){
  },
  mixins: [itemListenerMixin],
  methods: {
    /**
     * 事件监听相关
     */
    tabClick(index){
      switch(index){
        case 0:
          this.currentType = 'pop'
          break
        case 1:
          this.currentType = 'new'
          break
        case 2:
          this.currentType = 'sell'
          break
      }
      this.$refs.tabControl1.currentIndex = index;
      this.$refs.tabControl2.currentIndex = index;
    },
    backClick(){
      // console.log('back');
      this.$refs.scroll.scrollTo(0,0);
    },
    contentScroll(position){
      // 1.backtop是否显示
      this.IsBackTop = -position.y > 1000

      // 2.决定tabControl是否吸顶
      this.isTabFixed = (-position.y)>this.tabOffsetTop
    },
    loadMore(){
      this.getHomeGoods(this.currentType)
    },
    swiperImageLoad(){
      this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop
      // console.log(this.tabOffsetTop);
    },

    /**
     * 网络请求相关
     */
    getHomeMultidata(){
      getHomeMultidata()
      .then(res=>{
        // console.log(res);
        this.banners = res.data.banner.list;
        this.recommends = res.data.recommend.list;
    })
    },
    getHomeGoods(type){
      const page = this.goods[type].page + 1;
      getHomeGoods(type,page).then(res=>{
          this.goods[type].list.push(...res.data.list);
          this.goods[type].page += 1;
          this.$refs.scroll.finishPullUp()
      })
    },
  }
}
</script>

<style scoped>
  #home {
    /* padding-top: 44px; */
    height: 100vh;
    position: relative;
  }

  .home-nav {
    background-color: var(--color-tint);
    color: #fff;
/*
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    z-index: 9; */
  }

  .tab-control {
    position: relative;
    z-index: 9;
  }

  .wrapper {
    overflow: hidden;
    position: absolute;
    top: 44px;
    bottom: 49px;
  }

</style>
